A computer network is a collection of interconnected computing devices that exchange data and share resources. In a packet-based network, such as the Internet, the computing devices communicate data by dividing the data into small blocks called packets. The packets are individually routed across the network from a source device to a destination device. The destination device extracts the data from the packets and assembles the data into its original form. Dividing the data into packets enables the source device to resend only those individual packets that may be lost during transmission.
Certain devices within the network, referred to as routers, maintain tables of routing information that describe available routes through the network. Each route defines a path between two locations on the network. Upon receiving an incoming data packet, the router examines header information within the packet to identify the destination for the packet. Based on the header information, the router accesses the routing table, selects an appropriate route for the packet and forwards the packet accordingly.
Virtual private networks (VPNs) are private data networks used to share data between two remotely located computing devices. VPNs may, for example, make use of a public network infrastructure, such as the Internet. For instance, a company with two different sites may securely transmit data between the two different sites via a VPN. VPNs may include numerous servers and other devices that provide services to host devices within a particular VPN. For example, a print server may provide printing services to the host devices within the VPN.